Philips Semiconductors Product data sheet
SC28L91
3.3 V or 5.0 V Universal Asynchronous
Receiver/Transmitter (UART)
2004 Oct 21 29
OPCR Output Port Configuration Register
Addr Bit 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0
OPCR OP7 OP6 OP5 OP4 OP3 OP2 OP1 OP0
0x0D 0 = OPR[7] 0 = OPR[6] 0 = OPR[5] 0 = OPR[4] 00 = OPR[3] 00 = OPR[2]
1 = Reserved 1 = TxRDY 1 = Reserved 1 = RxRDY/FFULL 01 = C/T OUTPUT 01 = TxC(16X)
10 = Reserved 10 = TxC(1X)
11 = Reserved 11 = RxC(1X)
OPCR[7]—OP7 Output Select
This bit programs the OP7 output to provide one of the following:
0 The complement of OPR[7].
1 reserved
OPCR[6]—OP6 Output Select
This bit programs the OP6 output to provide one of the following:
0 The complement of OPR[6].
1 The transmitter interrupt output which is the complement of
ISR[0]. When in this mode OP6 acts as an open-drain out-
put. Note that this output is not masked by the contents of
the IMR.
OPCR[5]—OP5 Output Select
This bit programs the OP5 output to provide one of the following:
0 The complement of OPR[5].
1 Reserved
OPCR[4]—OP4 Output Select
This field programs the OP4 output to provide one of the following:
0 The complement of OPR[4].
1 The receiver interrupt output which is the complement of
ISR[1]. When in this mode OP4 acts as an open-drain out-
put. Note that this output is not masked by the contents of
the IMR.
OPCR[3:2]—OP3 Output Select
This bit programs the OP3 output to provide one of the following:
00 The complement of OPR[3].
01 The counter/timer output, in which case OP3 acts as an
open-drain output. In the timer mode, this output is a square
wave at the programmed frequency. In the counter mode,
the output remains High until terminal count is reached, at
which time it goes Low. The output returns to the High state
when the counter is stopped by a stop counter command.
Note that this output is not masked by the contents of the
IMR.
10 Reserved
11 Reserved
OPCR[1:0]—OP2 Output Select
This field programs the OP2 output to provide one of the following:
00 The complement of OPR[2].
01 The 16X clock for the transmitter . This is the clock selected
by CSR[3:0], and will be a 1X clock if CSR[3:0] = 1111.
10 The 1X clock for the transmitter, which is the clock that shifts
the transmitted data. If data is not being transmitted, a free
running 1X clock is output.
11 The 1X clock for the receiver, which is the clock that samples
the received data. If data is not being received, a free run-
ning 1X clock is output.
SOPR—Set the Output Port Bits (OPR)
SOPR[7:0]—Ones in the byte written to this register will cause the corresponding bit positions in the OPR to set to 1. Zeros have no effect. This
allows software to set individual bits with our keeping a copy of the OPR bit configuration.
Addr Bit 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0
SOPR OP 7 OP 6 OP 5 OP 4 OP 3 OP 2 OP 1 OP 0
0x0E 1 = set bit 1 = set bit 1 = set bit 1 = set bit 1 = set bit 1 = set bit 1 = set bit 1 = set bit
0 = no change 0 = no change 0 = no change 0 = no change 0 = no change 0 = no change 0 = no change 0 = no change
ROPR—Reset Output Port Bits (OPR)
ROPR[7:0]—Ones in the byte written to the ROPR will cause the corresponding bit positions in the OPR to set to 0. Zeros have no effect. This
allows software to reset individual bits with our keeping a copy of the OPR bit configuration.
Addr Bit 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0
ROPR OP 7 OP 6 OP 5 OP 4 OP 3 OP 2 OP 1 OP 0
0x0F 1 = reset bit 1 = reset bit 1 = reset bit 1 = reset bit 1 = reset bit 1 = reset bit 1 = reset bit 1 = reset bit
0 = no change 0 = no change 0 = no change 0 = no change 0 = no change 0 = no change 0 = no change 0 = no change